1. Place potatoes and carrots in a single layer on a 15- x 10-inch jelly-roll pan. Drizzle with 3 Tbsp. olive oil, tossing to coat; sprinkle evenly with salt and pepper.
2. Bake at 400° for 45 to 50 minutes or until vegetables are tender and lightly browned, stirring once. Transfer vegetables to a serving bowl; stir in almonds, parsley, and, if desired, lemon juice. Toss to coat.